Former tobacco lobbyist Victor Crawford in a 1995 interview with JAMA (Journal of the American Medical Assn) talked about one of the ways Big Tobacco tries to skirt the health issue by attacking the messenger.

JAMA:

You commented in some news stories I've seen on the philosophy. "If you can't attack the message, you attack the messenger."

Mr. Crawford:

That's also the "Nazi" technique. Here's how we do it. I'd say, "Now you've heard all these witnesses who say that smoking causes lung cancer and emphysema and heart conditions. Now, ladies and gentlemen of the county council, the jury is still out on that issue. There is right and wrong probably on both sides, there are scientists on both sides, some agree, some don't agree, and that's not settled and cast in stone yet. But that's not the big issue. Let the medical people determine that issue. That's not the issue before you.

The issue before you is the constitutional basic right of citizens to be able to choose their lifestyle and what they want to do. And these people are trying to take away that right."

So now, I've gotten away from the message and I am attacking the messenger, and I start raising hell about them and wave the flag and play the Star Spangled Banner, and if it's done right, the message gets lost. It's the messengers who are on trial -- and often the messengers are not equipped to defend themselves.